The subject matter described herein relates generally to turbine engines and more particularly, to combustor assemblies for use in turbine engines.
At least some known gas turbine engines ignite a fuel-air mixture in a combustor assembly to generate a combustion gas stream that is channeled to a turbine via a hot gas path. Compressed air is delivered to the combustor assembly from a compressor. Known combustor assemblies include a combustor liner that defines a combustion region, and a plurality of fuel nozzle assemblies that enable fuel and air delivery to the combustion region. The turbine converts the thermal energy of the combustion gas stream to mechanical energy used to rotate a turbine shaft. The output of the turbine may be used to power a machine, for example, an electric generator or a pump.
At least some known fuel nozzle assemblies include tube assemblies or micro-mixers that enable mixing of substances, such as diluents, gases, and/or air with fuel, to generate a fuel mixture for combustion. Such fuel mixtures may include a hydrogen gas (H2) that is mixed with fuel to create a high hydrogen fuel mixture that is channeled to the combustion region. During combustion of fuel mixtures, at least some known combustors may experience flame holding or flashback in which the combustion flame travels upstream towards the fuel nozzle assembly. Such flame holding/flashback events may result in degradation of emissions performance, overheating, and/or damage to the fuel nozzle assembly.
In addition, during operation of at least some known combustor assemblies, combustion of high hydrogen fuel mixtures may create a plurality of eddies adjacent to an outer surface of the fuel nozzle assembly. Such eddies may increase the temperature within the combustion assembly and/or induce a screech tone frequency that induces vibrations throughout the combustor assembly and fuel nozzle assembly. Over time, continued operation with increased internal temperatures and/or such vibrations may cause wear and/or may shorten the useful life of the combustor assembly.